The word prognatus as written on the Sarcophagus of Lucius Cornelius Scipio Barbatus (280 BC) reveals the full development of the Latin R by that time the letter P at the same time still retains its archaic shape distinguishing it from Greek or Old Italic rho. The reference is also found in Ben Jonson's English Grammar. In William Shakespeare's Romeo and Juliet, such a reference is made by Juliet's nurse in Act 2, scene 4, when she calls the letter R "the dog's name". A good example of a trilled R is in the Spanish word for dog, perro. This Latin term referred to the Latin R that was trilled to sound like a growling dog, a spoken style referred to as vōx canīna ('dog voice'). The letter R is sometimes referred to as the littera canīna (literally 'canine letter', often rendered in English as the dog's letter). In Hiberno-English the letter is called /ɒr/ or /ɔːr/, somewhat similar to oar, ore, orr. In Middle English, the name of the letter changed from /ɛr/ to /ar/, following a pattern exhibited in many other words such as farm (compare French ferme) and star (compare German Stern). This name is preserved in French and many other languages. The name of the letter in Latin was er ( /ɛr/), following the pattern of other letters representing continuants, such as F, L, M, N and S. 4.3 Ancestors and siblings in other alphabets.4.2 Calligraphic variants in the Latin alphabet.4.1 Descendants and related characters in the Latin alphabet.